Football commentator how so sharply?

Very often he did not at the scene, perhaps like us, are sitting in front of the TV watch the game, but television in the players a shot, he seems to know he was outside the instep / inside the feet, or else parts. This is a rule of thumb do, whether what he said really that accurate?

Open carts2010-01-20 14:09:16 +0000 #2

from the ball to determine the speed of rotation and the ball out of the general playing can often be seen outside the instep or inside the instep.

Results ball into the2010-01-20 14:46:18 +0000 #3

you are not often watching it, it's too simple, I can. Experienced fans a look at the posture of this person know who is.